


Half Cousins

by orphan_account



Series: Arijon short fics [1]
Category: A Song of Ice and Fire & Related Fandoms, A Song of Ice and Fire - George R. R. Martin, Game of Thrones (TV)
Genre: Alternate Universe - High School, Alternate Universe - Modern Setting, Consensual Underage Sex, Eventual Smut, F/M, Fluff, Fluff and Smut, Prom, Smut
Language: English
Status: Completed
Published: 2018-05-17
Updated: 2018-07-08
Packaged: 2019-05-08 02:38:01
Rating: Not Rated
Warnings: Underage
Chapters: 4
Words: 3,974
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/14684688
Author URL: https://archiveofourown.org/users/orphan_account/pseuds/orphan_account
Summary: The first of (hopefully) an on-going series of prompt based Ari/Jon short fics.Based on a sugestion by The German Bear: “Lyanna and Elia both dump Rhaegar and end up together to raise Aegon Rhaenys and Jon who has a crush on his step cousin”In which Jon grew up in love with his beautiful half cousin Arianne. After Arianne drops some flirtatious hints, he takes the plunge and asks her to be his date to senior prom. You can guess what ensues.





	1. Chapter 1

Until Jon was ten, he’d honestly thought that Elia and Lyanna where both his biological parents. Somehow. It wasn't as if he didn't know how the whole process worked, he’d just… never applied it to his specific scenario. He’d assumed… he actually had no idea how he’d explained it to himself in his head, but it had made sense. To him at least. 

Then his moms had told him about a possible meeting with his biological father, and he’d been left flabbergasted. 

Once he’d fully understood the situation, that Lyanna had been impregnated by Elia’s husband, Lyanna and Elia had met accidentally, taken joint revenge against the cheating asshole, realized they got along, and decide to jointly raise three kids, he’d realized something else: Arianne wasn't his real cousin. 

Arianne Martell was Elia’s niece and Egg and Rhea’s cousin. Until the dad bomb dropped, he’d always assumed she was his cousin, too, which had been a problem. He didn’t understand all family dynamics, but he knew enough to know you weren’t supposed to fall in love with your cousin. 

Which was exactly what he had done. 

Arianne was about five years older than Jon. And, like many young children, Jon viewed older people as some kind of gods. By the time he was seven, he was utterly certain she was the most beautiful being ever. Whenever their sides of the family met up, he followed her around like a puppy. He would have done anything for her. She had been his first crush, the reason he had never told any of his friends who he liked. 

It hadn’t gotten better as he got older. When he was nine and puberty was rearing its ugly head, she’d been on his mind more and more often, usually accompanied by some body functions he didn’t yet understand. When he was twelve and finally learned that the thing between his legs was good for more than just pissing, she had featured in the scenes in his head. Usually in the small bathing suits she wore when they went on family vacations to the beach. Or in the tight jeans that made her ass look like a vision. Or nothing at all. 

Arianne had always been a positive presence. She had been babysitter, tutor, soccer practice picker-upper, and just a generally reliable figure. As he made the transition from tween to teen, their relationship had shifted from big cousin/little cousin to close friends. She made more risqué jokes, and they hung out without other family members in tow. Once, to help out with a bet, Arianne had even let Jon say she was his girlfriend to one-up a snarky asshole in his class for shits and giggles. 

Starting around junior year, she had started mildly flirting with him. She called him handsome, and not in the fawning, cheek-pinchy way his moms did, but with a smirk and a wink that got him simultaneously hard and terrified all at once. Then there were the times she openly complained about her boyfriend and lamented the fact that he was too young. And when she would poke him and ask if he had a girlfriend yet, and when he said he said no she would giggle and joke about keeping him to herself. 

All this was running through Jon’s head as his finger hovered over the send button. Senior prom was a week away, and he, of course, was dateless. Jon had never been one for large groups of people, but he even he felt he would regret going the entirely of high school without attending a single dance. 

After much internal deliberation, he sent the text. If this went south, it would be awkward as all hell to explain. 

 

Thankfully, Arianne said yes. She said she thought it would be fun to go to prom, almost like being back in high school for a night. 

She wore a purple dress, with lace that was almost too revealing for a high school dance. Her hair was done in ringlets that went down her back. She gave off the air of a princess. A sexy princess that made his tongue tied and his pants tight. 

He picked her up at Seven to take her to dinner. And so began the most torturously amazing night of Jon’s young life.


	2. Chapter 2

**Summary for the Chapter:**

> Before going to the dance with Arianne, Jon had has to get past her guardians: her uncle and her cousins.

Jon parked his car in front of Arianne’s house and exhaled heavily. He checked his breath. He fixed his hair. He checked his breath again. He checked he had the tickets. Eventually, when he ran of things to check, twice, he grit his teeth and got out of the car.

The walk up the Martell’s driveway felt like a march across no-man’s-land. He reached the door and almost checked his breath again before he knocked. His mind was going a mile a minute as he stood waiting.

 _Don’t stand too close to the door,_ he thought. _Straighten up, good posture. Not that straight, you’ll look like you have stick up your ass. Maybe this was a bad idea. Maybe it’s not too late to-_ shit _, the door’s opening, drop the brooding look and be friendly!_

He put on his best smile as Arianne’s uncle Oberyn opened the door.

“Hey, Jon, come in,” he stood aside as Jon entered tentatively. He shook Oberyn’s hand and saw he was smiling, but he he didn’t feel reassured. If Oberyn was here, it was likely that Arianne’s _other_ cousins were also here. And they had never been known to given an easy time.

“Arianne is still getting ready,” Oberyn told him. “You can have a seat in the living room.”

Jon nodded. He had been to the house before, so he knew where to go. He took a seat in an armchair and tried to keep from fidgeting. Oberyn took the seat across from him. He leaned back and put his feet up on the coffee table. It was a power move. He was at ease and Jon wasn’t. Jon resisted the urge to look at his watch, or up the stairs that led to Arianne’s room.

After a minute, Jon decided he wasn’t helping himself by being quiet. “How have you been?” he asked Oberyn, breaking the silence.

Oberyn nodded and looked at him with what might have been approving. “I’ve been doing well, thank you, Jon. How are you?”

“Fine,” he responded too quickly. He was obviously nervous. “How’s Ellaria?”

“She’s doing great. She and the younger girls are at her father’s house,” he sat up a little straighter. “What have you been up to lately?”

“Well, track season just wrapped up, so my afternoons and weekends are free now,” he said. He relaxed a bit. He could talk about running for days. “It’ll be weird to not have to do summer practice anymore.”

Oberyn nodded again. “And what have been doing in your free afternoons?”

“Yard work, mostly,” he admitted. “Elia and Lyanna are getting all the work they can out of me before I leave.”

Oberyn chuckled at that. Jon felt like he might finally be in the clear, then Oberyn’s face turned on a dime. “So what exactly are your plans for tonight?” he asked, coldly courteous.

“Just take her to dinner, then the dance, and have some fun,” he said after recovering from what felt like a mini heart attack. “We’re going to meet Sam and Gilly, and Sarella.”

Oberyn just looked him over. Jon had to actively keep from fidgeting under his gaze.

“Uh, is Doran here?” he asked. Arianne’s father was much less intimidating than her uncle. Actually, that was probably why Oberyn was the one to greet him, now that he thought about it.

“Doran is visiting Quentyn for the weekend,” Oberyn grinned just a bit. _He’s not here to save you_ , he seemed to say. “What time were you planning on having her home?”

Jon ran through his options in his head. Too late and he was a delinquent, too early and he was a pushover. “Whatever time she wants to come back,” he said. It wasn’t the perfect answer, and probably wouldn’t have satisfied Doran, but it just might work with his brother.

It seemed to. “Good answer,” he looked to the top of the stairs. “Ah, here’s the lovely lady now.”  
  
Jon followed his gaze to see Arianne descending, her cousins in tow, looking like a princess out of movie. Her dress was sheer and purple, framing her curvy body excellently. It wasn’t too low cut, but it was low enough to tease, to make promises of hidden wonders. The length of the dress was similar, being just low enough to be modest enough for a high school dance. Her shoes were high-heeled strappy sandals that went up to her knees. Jon was glad he was still holding the box for the corsage. He moved it in front of his crotch, hoping it was enough to hide the new tightness in his pants.

When she reached the bottom of the stairs, she shot him a smirk that sent shivers down his spine. He had to take a second to untwist his tongue. “You look amazing,” he said.

Arianne’s smile widened. “Thank you. You don’t look so bad yourself.”

“Jon!” Tyene exclaimed as she rushed up to hug him. “Oh, it’s been so long, you’ve gotten so tall!” she gushed. Then she leaned on closer and whispered in his ear. “I don’t care if you’re family or not. You hurt her, we kill you.” Behind Arianne, Jon could see Nym smiling menacingly, and Obara cracking her knuckles.

“Message received,” he whispered back. Tyene let him go, all hints of intimidation gone, and ruffled his hair.

“Have a great time, you two!” She said.

He glanced at Arianne. She was still smirking. It was frightening, yes, but it most defiantly promised a good time.

And by god, was he in for one.

**Notes for the Chapter:**

> Yes, this was supposed to be two parts. Yes, this was supposed to not take this long. No, I will not be getting better at time management. 
> 
> Will anyone mind too much if dinner and the dance are one chapter and then the smut gets its own chapter for the finale? That might be what I end up going with. 
> 
> Always open to new prompts, and feedback is always appreciated. Thanks for reading.


	3. Chapter 3

“So what did Tyene say?” Arianne asked as soon as they were driving away. She leaned over and fixed his hair where Tyene had ruffled it, and he had to exert considerable effort to keep from grabbing her hand and kissing it. Then kissing the rest of her.

“How did you know she said something?”

“Because when she hugged you, your face curdled like milk,” she laughed.

Jon sighed in resignation, but grinned all the same. “Just that if I hurt you, I would pay, half cousin or not.”

Arianne nodded. “To be expected. What was Oberyn like?”

Jon just shrugged. “About like the stereotypical protective dad, except he was an uncle.”

“Yeah, my dad uses him to intimidate all my boyfriends.”

“Has he ever done it himself?” It was hard to imagine Doran as intimidating. He also tried not to dwell in the fact he was being treated like a boyfriend. He didn’t want to get ahead of himself.

“Nah, he couldn’t pull it off. Besides, Oberyn enjoys it too much.” Her hand drifted over to where his was, resting on the gear shifter. He felt his pulse quicken. Arianne did that to him. “So what’s the plan for tonight?” She asked.

“We’ve got reservations at Highgarden, and we’re meeting Sam and Gilly. Sarella will be there, too. After that, we head to the dance.”

She tilted her head at him and batted her eyelashes. “Any plans for after the dance?”

Jon gulped. “Uh, I didn't have anything in mind. Was there something you wanted to do?”

“There is _something_ that I think could be fun,” she said. She was twirling a ringlet of hair in her fingers. Jon had to mentally slap himself to refocus in the road. _There’s no fucking way this isn’t intentional_ , he thought.

“I’m up for whatever you are,” he said, trying not to sound as excited or nervous as he felt.

“Good,” Arianne patted him in his leg. “Don’t worry, we’ll have a great time.”

  
Looking back, Jon wasn’t quite sure how he managed to get through the car ride without combusting. It wasn’t a long drive, maybe ten, fifteen minutes at most, but Arianne had spent the entire time teasing him every way she could. She had stretched out in the seat, causing her breast to strain against the fabric of her dress. She had had looked at him out of the corner of her eyes and licked her lips. Her hands had rubbed all of over his thighs and biceps, squeezing them through his clothes, but in quick little movements to punctuate points in their conversation, instead of just keeping her hand there.

He was half surprised his didn’t explode from sensory overload then and there. And then she somehow managed to kick it up a notch in the restaurant.

  
They met Sam and Gilly inside, and Sarella showed up soon after. Sam and Sarella knew each other because Sarella had rescued Sam from angering the self-proclaimed Council of Nerds during his first week of school while crossdressing. Long story.

Arianne sat next to Jon, across from Sam and Gilly, with Sarella at the end of the table. It took all of two minutes for her to begin teasing him again. Jon did his best to carry on conversation as normal despite Arianne’s hand all over his thigh, or her leg being intertwined with his, but he was pretty sure everyone noticed how little he was talking or how red in the face he was.

“Hey, Jon, you alright, man?” Sam asked. “You look tense. Like, extra tense.”

Jon couldn’t help but glance over at Arianne, who looked immensely proud of herself. “No, I’m fine, buddy. Maybe a little hungry is all.”

Sam shrugged and went back to talking about a new book restoration project he was working on, but Sarella wasn’t as fooled. She knew good and well what Arianne was up too. She wasn’t going call her out on it, of course, though. In fact, she was finding it quite entertaining.

The dinner teasing reached its zenith when she actually cupped him there at the table. Not sure he could take it anymore, he excused himself to go to the restroom. He needed to clear his head.

After holding a paper towel soaked in cold water against his head and thinking about potatoes and math for a solid five minutes, he started to get things back under control.

That is, until he ran into Arianne in the hallway outside the bathroom. For the first time of the night, she wasn’t grinning.

“Jon, are you sure you’re alright?” She asked, sounding concerned.

He nodded. “Yeah, just a little…” _sexually pent-up? On the verge of combustion? Really wanting to take you back into the bathroom and make out with you?_ “...Overwhelmed.”

Arianne put her hand on his arm, not in a sexual way, but a reassuring one. “Jon, if what I’ve been doing all night is making you angry, I’m sorry, and I promise I’ll stop.”

“No, no!”, he immediately exclaimed. “I mean, I’m not angry, it’s just that when the woman of your dreams has been touching you all night looking like that,” he shrugged. “It can make it a little hard to think.”

Arianne’s smile immediately returned. “‘Woman of your dreams’, huh? I had no idea I was held in such high regard. But seriously, do you want me to stop? I will if it’s bothering you.”

Jon shook his head. “Nah, I said I was up for anything, right?”

“Ok,” she got up on her tiptoes and gave him a kiss on the cheek. “You know,” she said as she turned around, “you can tease me back it you want.”

  
Jon decided he would try that when he got back to the table. Arianne’s chair was already scooted closely to his, so he didn’t have to move. She was already back when he returned.

This time, Jon was the one to slide a hand over, he began slowly running it up the inside of her thighs, taking special care not to be seen. His fingers danced across the smooth skin of her legs, and she shot him a sideways smile with a hungry glint in her eyes.

Arianne was right. They were going to have a great time.

  
The drive to the dance was conducted in much the same way as the drive to the restaurant, except that Arianne had upped the ante by using more scandalous language. Now that Jon knew the game and had agreed to play, there was really no point in being subtle anymore.

“So when you say ‘woman of your dreams’,” She asked, playing innocent, “what kind of dreams are you referring too?”

Jon’s hands tightened on the wheel.

“What happens in these dreams?”

He could feel himself starting to heat up.

“Would like them to come true?”

He’d never been so relieved to see the school so much in his entire life.

The dance itself was more fun than he had expected. Of course, the fact that Arianne was there, and by far the sexiest girl there, contributed to that.

The music wasn’t his type, but he’d picked up a while ago that just enjoying it and not worrying about it made for a better time that standing there curmudgeonly and being bitter about it.

The one thing he was bitter about was all the looks Arianne was getting, but it didn’t really matter. She was, after all, there with him. Getting worked over nothing would ruin the mood.

So instead, he just danced with Arianne for two hours. And, one time with Sam. They would laugh about that later.

Arianne kept her teasing tame mostly at the dance, seeing as they were now in public, but she still found a way to keep Jon worked up. He’d nearly lost it when she held his gaze his gaze as she danced to “The Hips Don’t Lie”, giving him a show that would most definitely appear in his dreams later. At times, he found himself staring at her body, how divine she looked in that tight purple dress, and he realized just how badly he wanted to tear it off her.

He was pretty sure that was the point.

The last dance they stayed for was the obligatory slow dance. Jon had his hands on her hips, holding her in close as the swayed to the music.

“I’ve had a lot of fun tonight,” she stepped in closer and rested her head on Jon’s chest. “I’m really glad you asked me this.”

“Me too.”

They stayed there for the rest of the song, just enjoying each other’s presence. Then the slow song ended and Arianne looked up at Jon. She held his gaze for a long second, then she kissed him. At first Jon was caught off guard, but he just closed his eyes and kissed her back. When they finally broke apart, the glint in her eyes had come back.

“Come on,” she grinned. “Let’s go end prom night with a bang.”

**Notes for the Chapter:**

> Now all that’s left is finale smut. 
> 
> Feedback, prompts, and criticism appreciated. Thanks for reading!


	4. Chapter 4

**Summary for the Chapter:**

> Finally getting this wrapped up. Sorry for the wait, but hey, smut!

The final car ride back was the hardest so far. As soon as the got in, Arianne told him to start undressing.

“So that when we get there, we don’t have to worry about messing up that nice tux,” she said, eyeing him up and down. It sent shivers through him.

He was down to just his white shirt and pants when they arrived, and Arianne led him by the hand inside and up the stairs.

“Don’t worry about getting caught, they’ve all gone home,” she told him.

That threw Jon for a loop. “Really?” He asked. “ After that big show when I picked you up?”

Arianne just giggled. “They aren’t really worried about you, they just thought it would be to much fun to miss.”

Jon grunted, but he couldn’t bring himself to be annoyed, given the circumstances. So long as they didn’t interrupt now, they could torment him all they wanted.

 

They started kissing as soon as her door closed behind them, slowly at first. Arianne was warming him up. She kissed him as she began to unbutton his shirt, and he held her face in his hands.

“Unzip my dress,” she asked him between kisses. He obliged, and soon it was off, and his shirt came after. Their bodies pressed together, and Jon reached down to pick up one of Arianne’s legs as she wrapped her arms around him tightly. She gasped as he moved to her neck and collarbone, suckling her pulse.

“Bed,” she whispered breathlessly, and Jon stepped to it and set her down.

His eyes were alight and his breathing was heavy as he leaned over, waiting. It betrayed a hint of nervousness, but she could see he was eager to please.

She reached behind her and undid her bra, and she watched as his pupils seemed to double in size. She couldn’t help but smirk.

“How long have you been waiting to see these?” She teased him.

“Longer than I want to think about,” he growled as he closed the distance. He started slow, kissing the valley as his hands caressed her, and she leaned back on the bed. She ran her hands through his hair as he began to tease her nipple, blowing on it and lightly pressing it with his tongue. She sighed in content when he finally took it into his mouth.

He stayed there a while, then he moved down her body, leaving a trail of soft kisses as he went, until he came to the hem of her underwear. He rubbed her over the fabric, feeling how wet she was, and he pressed his tongue against her lightly.

Her grip on his hair tightened. “Mmmhhh, Jon,” she gasped. “I know I said you could tease me back, but this is just mean,”

He smirked up at her. “Payback,” he whispered as he removed her last piece of clothing. He began to lick her slowly, tasting her and delighting in the little movements she made as he worked. He held her hips as he kissed between her thighs and breathed heavily on her sex. She moaned and let out little gasps at his touches, and he began to go faster and deeper.

Arianne wrapped her legs around his head, holding him in place, as if he would ever want to leave. Soon, her breathing became erratic, and Jon held his mouth against her as she came, coating his face and filling his mouth.

She pulled him up on the bed and rolled him over, putting him on his back. She pulled his pants down and straddled him, giving him a moment to catch up.

“Ready, Jon?” She asked, taking his hands in hers.

He nodded. “God, yes,” he gasped, looking at her like she was a divine revelation.

Arianne lowered herself down on him slowly, letting out a groan of pleasure to match his. She began to roll her hips slightly, and soon Jon was following suit, moving in time with her. They began to speed up, going so fast they caused the bed to rock.

“Don’t stop,” she told him. “don't you dare stop, Jon!”

“Ari,” he gasped, “I’m getting close,”

“ _Jon_!”

“ _Arianne_!”

They let out matching cries, and his release triggered hers, and she collapsed onto him. They panted, catching their breath and coming down from their high. Arianne moved in close and nuzzled Jon’s chest as he wrapped her in his arms.

“Some prom night, huh?” Arianne asked when she found her voice.

“Best I’ve been too,” Jon agreed.

Arianne looked up at him and smirked. “You haven’t had any others.”

“And I don’t need any others,” he said. “This one was perfect.”

She gave him a lingering kiss. “I had a lot of fun tonight,” she said.

Jon nodded. “Me too.”

“We’re doing this again.”

Jon looked confused for a moment. “Going on a date or…?”

She kissed him again. “Both.”

**Notes for the Chapter:**

> Sorry again for this taking so long. And being short. Sex scenes aren’t the easiest thing for me to write, and wanted to try to keep from getting gratuitous or porny. But it is what it is.
> 
> I’m still taking prompts, but that will come to end shortly, so if you have an AU or a scenario that you really want to see Ari and Jon in, feel free to let me know, but I want to finish my other unfinished projects, so it may be awhile before I can get to it. Thanks for reading, feedback and criticism always appreciated!

**Author's Note:**

> This is the first half. The second will come eventually. I promise. Criticism apreciated as always, and I would love to hear story suggestions. 
> 
> Thanks for reading!


End file.
